1. Field of the Invention
The present invention relates generally to medical and surgical equipment and, more particularly, to an orthotic device for one of the joints of the human body, such as the ankle or wrist, wherein the device includes structure for mimicking one of the muscles and the associated tendons extending across the joint.
2. Discussion of the Prior Art
Treatment of a sprained joint often involves restricting flexation of the joint against movement in a direction which would further injure or place undue stress on the injured ligaments, muscles or tendons. Immobilization of the joint is commonly accomplished by placing a brace, having one or more rigid splints, on the joint. For example, in the case of a lateral sprain of the ankle joint, a traditional brace includes a pair of rigid splints disposed along the inner and outer sides of the lower leg and ankle joint for preventing inversion and eversion of the ankle joint (i.e., turning in and out of the foot, respectively). Similar to the ankle brace, a conventional brace for treating a wrist joint sprained due to excessive flexion (i.e., excessive turning of the hand downwardly) includes a rigid splint extending along the underside of the arm and onto the palm of the hand for bracing the hand in a "cocked up" position. Of course, this type of wrist brace prevents flexion of the wrist joint out of the "cocked up" position. The hand is typically secured to the splint by a bandage or cloth sleeve so that extension of the wrist joint (i.e., turning of the hand upwardly) is also prevented.
In any case, a "splint-type" brace is often useful during the acute stage of the injury because immobilization of a joint may be desired as the injured tissue initially begins to heal. However, this type of brace is typically bulky and therefore cannot be worn inside a shoe or clothing. Further, discomfort is often a problem with a "splint-type" brace, especially when the brace is tightened about the joint to reduce swelling. Another serious problem with a "splint-type" brace is that essentially all joint function is prevented, which restricts activity involving use of the joint and, more importantly, is undesirable during the rehabilitation stage of the injury. That is, it is desirable to progressively reduce the degree of immobilization of the joint during rehabilitation so that the injured muscle is strengthened as the joint is returned to normal activity. Moreover, immobilization of the joint may cause atrophy in both the injured and non-injured tissue. For example, if the extensor digitorum tendon is strained due to excessive flexion of the wrist joint and a "splint-type" brace, as described above, is used to immobilize the wrist joint, eccentric contraction of the extensor digitorum muscle and concentric contraction of the flexor digitorum, along with contraction of other muscles associated with the wrist, are prevented. The treatment afforded by the brace consequently does not focus only upon the injured tissue, and accordingly, joint function is overly restricted by the brace.
Wrapping of the joint with a cloth bandage or tape is another conventional technique for immobilizing a joint. Although cloth or tape wraps are more comfortable and less bulky than "splint-type" braces, the wraps likewise immobilize the joint and therefore present the same problems of atrophy, lack of performance during the rehabilitation stage of the injury, and excessive restriction of joint function. In fact, tape and cloth wraps are traditionally more restrictive than the "splint-type" braces because the wraps encircle the joint and adjacent body parts. For example, a "splint-type" ankle brace for lateral sprains of the ankle joint, as described above, sometimes allows limited dorsi and plantar flexion of the ankle joint. Cloth and tape wraps are also difficult and cumbersome to apply by the wearer and therefore often require assistance from another person, such as a trainer. Further, wrapping of the joint must be done carefully, otherwise the cloth or tape wrap may cut off circulation if wrapped too tightly or provide virtually no support if wrapped too loosely.
Braces have been designed for use during the rehabilitation stage of injuries. Rehabilitative braces typically include a pliable sleeve formed of elastic material for placement on the joint and adjacent body parts. For example, a rehabilitative ankle brace traditionally comprises a boot-shaped sleeve that is tightened about the lower leg, ankle joint and foot by suitable lacing. Although this type of brace is comfortable and capable of being worn within a shoe, the sleeve itself provides little support to the joint. Accordingly, the sleeve would not be effective during the acute stage of an injury because of its failure to sufficiently restrict movement of the joint. Even when the sleeve is used for rehabilitative purposes, it restricts movement of the joint in virtually any direction and consequently fails to focus only on the injured tissue. It will be appreciated that rehabilitative sleeves are also often used as a prophylaxis for reducing the risk of re-injury.
Rehabilitative sleeves have been provided with various structure in an attempt to broaden their application to include treatment during the acute stage of the injury. For example, sleeves have been provided with rigid splints inserted into pockets formed along the sleeve. However, this type of brace still presents the same problems noted above and still lacks sufficient versatility to have effective application during all stages of the injury. Other types of orthotic devices for use during the various stages of an injury have been developed. In general, however, multi-stage orthotics tend to have complex and expensive constructions and are difficult to install.